- Since the 13th century, Rajshahi, named “Silk City,” has been known for its finest silk, which local growers have produced.
- Earlier, the product was named Bengal silk or Ganges silk. Considering the prospects and reputation of the trade, the then-Pakistan government started producing silk officially. Consequently, it established a silk factory in Rajshahi in 1961, which washanded over to Bangladesh Sericulture Development Board in 1978.
- The silk sector in Rajshahi grew as farmers of the neighboring districts used to produce high-quality silk yarns by the larvae of moths fed on fresh mulberry leaves, which were later used for luxurious clothing items. There are three types of silk produced in Rajshahi: mulberry, endi and tassar, with mulberry silk being the finest and most expensive.
- However, Bangladesh’s once-famous silk industry has faced difficulties in recent years, including the excessive dependency on imported low-cost yarn and different bacterial and viral diseases triggered by constantly variable temperatures and humidity.
Bangladesh’s famous Rajshahi silk industry has been struggling in recent years for many reasons, including the excessive dependency on imported low-cost yarn. The recent erratic weather has been worsening the situation, as the local mulberry and silkworm producers are now experiencing different bacterial and viral diseases, which eventually reduce the silk production rate.
According to a study, the weather in Bangladesh and the current methods used to raise silkworms strongly encourage the spread of bacterial and viral infections. The situation for the silk manufacturer is becoming more difficult due to shifting weather patterns.
A notable lepidopteran insect used to produce natural silk fiber is the silkworm Bombyx mori L. It is vulnerable to several diseases and pests. The environment highly influences the growth and development of silkworms. As a result, worms weaken and are more susceptible to various infections, said Kamrul Ahsan, a co-author of the study.
In four rearing seasons known as per the name of Bengali calendar months Vaduri (August to September), Agrahayan (November to December), Choitro (March to April) and Joistho (May to June) practiced in the northern part of Bangladesh.
About 40-50% reduction of average cocoon yield occurs during the two seasons of Joistho and Vaduri, when the temperature and humidity go to extremes. In Bangladesh, the summer (or hot) months usually start in April and end in October.
The ideal temperature for producing a good quality yarn and proper larvae growth is 25 degrees Celsius (77 degrees Fahrenheit) and relative humidity.
However, a recent study shows that the region is frequently experiencing temperatures between 25 and 35 degrees Celsius (77-95 degrees Fahrenheit) in the hottest season and 9-15 degrees Celsius (48-59 degrees Fahrenheit) in the coolest season. In summer, some of the hottest days reach temperatures above 40 degrees Celsius (104 degrees Fahrenheit) or more; in winter, temperatures can fall to around 5 degrees Celsius (41 degrees Fahrenheit).
The increase in temperature and humidity in causes the alimentary canal, or gastrointestinal tract, to become dysfunctional, which promotes a silkworm disease called flacherie. This is also producing low-quality mulberry leaves. The study says a high rate of infectious bacterial growth and the emergence of bacterial flacherie occur due to the larva’s inability to manufacture enough antibacterial factors from leaves with insufficient nutritional content.
About 700 farmers have actively engaged in mulberry and silkworm production in the region, as per the Bangladesh Sericulture Development Board (BSDB) statistics.
“During the four raising seasons in a year, many of us fail to harvest crops, and some others only partially do so,” said Bhadu Sheikh, a mulberry and silk cocoon farmer in Rajshahi.
The only commercial is to eliminate big stocks of worms in case of infection to prevent the disease from spreading because there are no specific preventive measures for the occurrence and spread of the disease other from sanitized breeding and rearing practices. This makes a huge production loss for the farmers, said MD Abu Hanif, BSDB manager.
BSDB data show that the figure for produced silk yarn in 2017-18 was 40 metric tons, while the figure stood at only 7 metric tons in the 2022-23 fiscal period.
Silk City and the beginning of a downfall
Since the 13th century, Rajshahi has been known for its finest silk, which local growers have produced. Therefore, the city is named Silk City.
Earlier, the product was named Bengal silk or Ganges silk. Considering the prospects and reputation of the trade, the then-Pakistan government started producing silk officially. Consequently, it established a silk factory in Rajshahi in 1961. Later the factory was handed over to BSDB in 1978. It accumulated losses and closed on Nov. 30, 2002. Before closure, the factory had produced about 300 tons of yarn.
The silk sector in Rajshahi had grown as the farmers of neighboring districts used to produce high-quality silk yarns. They were experts in creating high-quality silk by the larvae of moths fed on fresh mulberry leaves, which were later used for luxurious clothing items.
The price range of an average quality Rajshahi silk sharee is about 5,000 takas ($46), while the premium quality sells at 20, 000 takas ($185) in the local market.
There are three types of silk produced in Rajshahi: mulberry, endi and tassar. Of them, mulberry silk is the finest and most expensive.
Until the beginning of the 1980s, the silk mills depended on local yarns. Later, the mills gradually increased their dependency on imported silk yarn from China due to the low cost.
Industry insiders say the price of 1 kilogram (2.2 pounds) of local yarn was 1,200 takas ($11), while the imported yarn cost 900 takas (less than $9). Consequently, the local yarn producers were losing their business and enthusiasm as they failed to compete with the imported yarn with zero tariffs from China.
Using the cost-effective Chinese silk yarn made a huge profit, and factories increased from around 20 to more than 100.
Meanwhile, China has been gradually hiking the price of yarn since the 1990s, as the industry was mostly dependent on Chinese yarn.
Currently, the price of 1 kg of Chinese yarn is around 7,000 takas ($65).
As a result of the high yarn price, the industry has gradually been losing its profits and customers, as the product prices have exceeded the margin. More than 100 factories produced silk-made products in the late 1990s, while the number stands at only 4 now.
Though the government has taken different initiatives, including promoting sericulture among the farmers with necessary support free of cost, and it also imposed a 25% import duty on Chinese yarn to revive the silk industry, the ongoing weather pattern has been making all the efforts in vain, said Hanif.
Banner image: A silkworm farmer from Rajshahi, Bangladesh. Image by MD Abu Hanif.
Rashid, M. A., Faroque, O. & Chowdhury, A. K. (2014). Sericulture Industry in Bangladesh: Problems and Prospects. American Journal of Economics. doi:10.5923/j.economics.20140403.02
Roknouzzaman, M., Mahdi, S. H. A. & Ahsan, M. K. (2016). Disease incidence of silkworm, Bombyx mori L. in different rearing areas and seasons of northern part of Bangladesh. University Journal of Zoology, Rajshahi University. 35:1-6. Retrieved from https://www.researchgate.net/publication/326258871_Disease_incidence_of_silkworm_Bombyx_mori_L_in_different_rearing_areas_and_seasons_of_northern_part_of_Bangladesh
Rahmathulla, V. K. (2012). Management of Climatic Factors for Successful Silkworm (Bombyx mori L.) Crop and Higher Silk Production: A Review. Psyche: A Journal of Entomology. Volume 2012. Article ID 121234. doi:10.1155/2012/121234
Nadiruzzaman, M., Rahman, M., Pal, U., Croxton, S., Rashid, M. B., Bahadur, A. & Huq, S. (2021). Impact of Climate Change on Cotton Production in Bangladesh. Sustainability 2021, 13(2), 574; doi:10.3390/su13020574